1. Field of the Invention
The field of the present invention relates generally to a system for distributing the I/O request load over the components of a network. More particularly, the field of the invention relates to distributing the responsibility for carrying out I/O requests among various servers on a network.
2. Related Art
For a number of decades, information has been shared among computers in many various forms. A popular form that has developed is the network file system which almost universally has four capabilities: (1) they share a view of a file system among multiple computers and allow normal file operations to be performed by them; (2) they have security to control who can do what to the file system; (3) they have byte-level file range locking which allows a method for multiple independent users of the file to coordinate changes to the file maintaining coherency, and; (4) they often are functional in a heterogeneous computing environment allowing different computers and different operating systems to share the same files system.
File and total data set sizes are increasing. Movement from analog to digital storage and manipulation of information and media continues to grow. Sustained bandwidth of storage is also increasing. Personal computers with enormous processing power are increasingly affordable.
Computer networks require file servers which frequently operate under the client/server paradigm. Under this paradigm, multiple clients make I/O requests which are directed to a particular resource on the network. A server on the network receives and carries out the I/O requests. When a server receives multiple I/O requests the server queues them and then services them one at a time. Once a queue begins to accumulate, subsequent I/O requests must sit in the queue until the previous I/O requests are serviced. As a result, the server can become a bottleneck in the network.
A single server in the network frequently manages the data structures for files corresponding to a particular resource. This arrangement prevents modification of the files corresponding to a resource by multiple servers. Such a modification would cause the file system to become corrupt since there would be no means of maintaining the data structures in a logical and coherent manner. As a result, a single server receives the I/O requests for a particular resource. If that resource is being heavily used, the server can develop a substantial queue of I/O requests while other servers on the network remain idle.
The use of a single server for managing files for a resource can also create network problems when the single server crashes and is no longer active on the network. Some networks will lose access to the resource in response to the crash. Other networks include a back up server which becomes engaged to manage the files previously managed by the crashed server. The backup server may also be subject to crashing. Further, the backup server is required to manage the I/O requests of two servers increasing the opportunity for the backup server to create a bottleneck or crash.
What is needed is an improved system and method for distributed processing over a network. Such a system would remove the bottlenecks and disadvantages associated with current distributed networks, while at the same time maintaining its advantages. Such a system would further allow the distribution of processes to function and be managed in a cross platform environment.